Complete Hobby King Lipo Protection Kit

[methods]

Resistor needs to be moved to the green line between the point at which the system taps in and the throttle. The idea is to limit the current going from the throttle into the short circuit created by the LVC board.

Maybe change the LVC names to LVC/HVC to be more accurate since they detect both conditions

Good job taking the time to draw up your system. That is how you succeed. I really like that schematic - easy to read and illustrates the system well. Thanks!

-methods

[ryan]

Thanks fractal. Can you tell me about the 500 resistor instead of 1000 like the Methods Throttle Retard cable? I'm also using a Lyen controller (18-fet). Do I need to switch that out of Methods' stock kit?

[dougnutz]

Thanks fractal. Can you tell me about the 500 resistor instead of 1000 like the Methods Throttle Retard cable? I'm also using a Lyen controller (18-fet). Do I need to switch that out of Methods' stock kit?

This is a compatibility issue discoverd about a month ago with at least some controllers such as my Lyens 12 Fet.
viewtopic.php?f=14&t=30216&start=195#p513137

If you're controller measures 5kOhm between the throttle signal wire (green) and ground then you need to use the 500Ohm resistor or you will not get full throttle out of your controller

[ryan]

The closest I could find was 470 Ohms (1/4w). Is that close enough?

[dougnutz]

The closest I could find was 470 Ohms (1/4w). Is that close enough?

I'm no expert but I do know that the resistor is there to limit current. I"m reasonably sure that 470 Ohms will work, but ideally you want someone like Methods to say "yes". Alternatively you could find another 1k resistor and parallel it with the original. That would work out to 500 Ohm.

However make sure your controller exhibits the same symptoms mine did. Either measure the resistance or hook up your battery without the throttle retard connected (throttle plugged into controller) and test your max rpm unloaded. Then plug in the retard pigtail and retest. In my case there was a significant loss of throttle and max speed (20% or so) with the 1k resistor.

[methods]

Yes... measure the input resistance of your Lyen controller.
One lead on the signal line
One lead on the signal ground

If you read a low number like 5kohms then you need to swap the resistor I sent for that 470 that you have.
The 1K that is in there will work - but you may lose a tiny bit of your top end.


-methods

[zukster]

You would use a 100.8V 10A CC/CV power supply or charger
Each board (4 of them) would need a "balance tap" coming out
To balance you would use 4 x Battery Medic ($15 each) or whatever you prefer.

* Try a BMSBattery Charger - we are ordering 4 or 5 of those.

I have a question about bulk charging with the Battery Medics and breaker board. Perhaps it is covered in a bulk charging thread but it is relevant here for people just wanting to order a charger for there total pack configuration.

For the above, I'm guessing that it is a 24S Total Pack. 24 x 4.2V max = 100.8V for the charger or power supply.

For this example, where do I buy a Power Supply that delivers exactly 100.8V? I'm guessing that this can be a bit higher and then the HVC breaker will just kick in. If you went lower, I guess your cells would never quite make it up to 4.2V each. I might not want one from BMSBattery necessarily.

How much tolerance is there in the Voltage being supplied? What does CC/CV mean?

Here was the link to the HobbyKing Batter Medic for people reading this:

http://www.hobbyking.com/hobbyking/stor ... em_6S.html

For my setup, I don't think I'll ever go over 18S or 18 x 4.2V = 75.6V.

[amberwolf]

For this example, where do I buy a Power Supply that delivers exactly 100.8V?

Use two in series. Or more. Get one that is adjustable voltage and adjustable current limiting, and the other two can be fixed voltage and current, as long as they will deliver at least the 10A you want, and are isolated (AC input is not electrically connected to the DC output at all, including ground).

If you don't need it to be portable:

Lab(oratory) power supplies (PSUs) work great for the former, and don't have to be a high voltage one, so you can get the cheaper low-voltage (even 0-5V would work) but higher current (at least 0-10A for yours) units. These are often found used for cheap, like the huge one Ryan just got.

Then for the latter, server PSUs are really cheap and are typically 12V or 48V output at fairly high currents. There is at least one HP (Hewlett-Packard) model that will work, and is well-documented here on ES (you'd have to search for it as I don't knwo the model #).

But any kind of PSU that is isolated will work for the bulk of the voltage supply. Series the outputs just like you would batteries, and then you just use the adjustments for voltage and current limit on the lab PSU to set up the final output voltage for your desired max voltage (wihtout the pack connected) and current (with the pack connected and charging), lock the controls down so you don't bump them or something, then you're set.

[dougnutz]

For the above, I'm guessing that it is a 24S Total Pack. 24 x 4.2V max = 100.8V for the charger or power supply.

For this example, where do I buy a Power Supply that delivers exactly 100.8V? I'm guessing that this can be a bit higher and then the HVC breaker will just kick in. If you went lower, I guess your cells would never quite make it up to 4.2V each. I might not want one from BMSBattery necessarily.

How much tolerance is there in the Voltage being supplied? What does CC/CV mean?

Here was the link to the HobbyKing Batter Medic for people reading this:

http://www.hobbyking.com/hobbyking/stor ... em_6S.html

For my setup, I don't think I'll ever go over 18S or 18 x 4.2V = 75.6V.

You don't want to rely on the hvc to be cutting off your charge. It's ment to be a fail safe.
There seems to be a lot of debate about how high you want to charge your pack but the Lipo experts around here generally don't charge all the way to 4.2 Mostly because there just isn't that much energy at the extream top end of the pack and it's generally agread that charging that high will lower your cycle life. If you are racing or using it for some application where cycle life isn't important than go for it.

In my case I ordered a bms battery charger and had it pre set to 4.13 v per cell (74.7v total) and it reliably drops my pack off at 47.8v . For the money it's a pretty good deal. But there are other people out there offering custom chargers if you prefer not buying from bms battery. If you buy the one that methods mentioned you can have it preset to 100.8v and then lower the voltage yourself to whatever you want. If you want plug and play I recommend having them do it, or buy one from methods

cc/cv refers to constant current/ constant voltage If I understand it right the charger starts out with constant current then switches modes to constant voltage as the pack nears the cutoff voltage of the charger. Pretty much every charger I have seen that is designed for lithium does this.

[zukster]

How much over 100.8V can you go, or for my 18S pack example, how much over 75.6V? Or is it better to go slightly under?

Use two in series. Or more. Get one that is adjustable voltage and adjustable current limiting, and the other two can be fixed voltage and current, as long as they will deliver at least the 10A you want, and are isolated (AC input is not electrically connected to the DC output at all, including ground).

That's a good idea. I have a lab type power supply I made from PC power supply. It gives me -5, 5, -12, +12 so I can not do quite variable but by combining, can get voltages such as 24v (+12, -12), 17v (+5, -12), 12v (+12, 0), 10v (+5, -5), 7v (+12, +5), 5v (+5, 0). That's why I was asking how much over your maximum pack voltage you can go. By combining, you can get pretty close to the target. For my pack for example, (3 x 24V) + 5V = 77V, which is just a bit over the total pack voltage of 75.6V. Alternatively, you could use 3 x 24V and then a variable unit to feed a more precise voltage (or perhaps (2 x 24V) + 12V + variable supply)).

I have some server power supplies available with APFC (active power factor corrected) that I can use to build something of good quality.

cc/cv refers to constant current/ constant voltage If I understand it right the charger starts out with constant current then switches modes to constant voltage as the pack nears the cutoff voltage of the charger. Pretty much every charger I have seen that is designed for lithium does this.

I'm pretty sure using server power supply will not deliver this.

[amberwolf]

Have you added variable current limiting to that PC PSU? If not, then it is not a true lab PSU and won't do what I described, which is to limit the current (without just shutting off, which is what most PSUs do when their limits are exceeded, if they don't blow up ), but also to limit it variably--to whatever you set it to, up to the max allowed or down to zero. So, be careful that whatever PSU you use for the variable parts does both variable voltage *and* variable current limiting, or else it will not be able to control the rest of teh series PSUs' current either.

[liveforphysics]

What Amber said is correct, all server and PC supplies do not have a CC mode at all. This means you must put something with a CC mode in series if you want to charge from them.

[fractal]

I'm just about to get a charger from BMS. I cant decide on what voltage/cell to set it. My pack is 24s. I understand now why you shouldn't set it to 4.2/cell to extend the life of the battery and compensatre for cell imbalances. But what should I get : 4.1, 4.13, 4.15???? Thanks for any help!

[methods]

Set it to 4.2V/cell or higher.
You can open it up and turn down the voltage... but there is not much room to turn up the voltage.

-methods

[zukster]

What Amber said is correct, all server and PC supplies do not have a CC mode at all. This means you must put something with a CC mode in series if you want to charge from them.

So use some server PS's in series with one smart PS that can do CC? How does this limit what's coming out of the server PS's?

I'm thinking that this might be just too much trouble when I can pick up a few IMAX B6-AC for 40 bucks each from HK. Maybe not the fastest but you can plug it into the wall or a 12V supply. There small/light enough that you could take one with you for longer trips with overnights.

http://www.hobbyking.com/hobbyking/store/__6478__IMAX_B6_AC_Charger_Discharger_1_6_Cells_GENUINE_.html

What were you guys thinking of taking as a portable 100.8V supply for when you just want to hijack an AC plug on a road trip to top up your pack?

[methods]

Here are those Battery Medic Test Results: Real vs Fake


-methods

[amberwolf]

So use some server PS's in series with one smart PS that can do CC? How does this limit what's coming out of the server PS's?

Because all current in a series circuit is the same. Lower current in one place and it drops in all of them.

[zukster]

So use some server PS's in series with one smart PS that can do CC? How does this limit what's coming out of the server PS's?

Because all current in a series circuit is the same. Lower current in one place and it drops in all of them.

Thanks, I'm more of a computer guy than electronics guy . I'm learning all the time though.

[methods]

I have made a correction to the picture of the Throttle Retard Assembly. It said TO HVC BREAKER when it should have said TO LVC/HVC/PARALLEL stack. Thanks to Jeff for the catching the error.... (somebody is paying attention )



-methods

[zukster]

Thanks to Jeff for the catching the error.... (somebody is paying attention )

I can't afford to pay attention. I spent all my spare cash on your boards

[ryan]

Hair dryer is perfect for Methods clear heat shrink. My torch was too hot and ended up splitting the shrink. Hair dryer was perfect.

[methods]

Yes... sadly that shrink is very thin. That is why I supply two layers. Just shrink it far enough to hug the connectors, don't go crazy and try to shrink it to 100%.

The original batch was a few mills thicker - and a prettier blueish color. This latest batch has a slight yellow tinge to it and is thin. Blame Matthew - he bought it

We are trying to find a new shrink supplier but it is harder than it sounds.

-methods

[zukster]

Here is how it works:
Normally - just plug in your charger and charge away!
If for some reason one of your cells gets overcharged this breaker will "lock up" and terminate charge. If this happens, please inspect your pack to determine the problem. After you have solved the problem - just press the green RESET button and you will be able to charge again.

The system is in the "ready" state - no need to press the RESET button unless something goes wrong. Thresholds are set at 4.29V so you should NOT need to press this button very often.... If you do, consider lowering your charge voltage or balancing your pack. -methods

So if we pretend that this is a relay, you mean its "Normally Closed?"

[methods]

Exactly

Like a latching relay really... if an HVC event occurs it blows the relay open and it stays open until you manually close it with the reset button.

-methods

[methods]

Somebody asked via Email if these are in stock.

Yes - 6S HVC/LVC/Parallel boards are in stock, HVC Breakers are in stock, LVC Retards are in stock, 5S and 6S extensions are in stock, and the super expensive 5S and 6S jumpers are technically available.

5S HVC/LVC/Parallel boards manufactured upon request

-methods